SEOUL, South Korea — North Korean leader Kim Jong Un oversaw a successful test of a new intermediate-range hypersonic ballistic missile (IRBM) on Monday, state media KCNA said on Tuesday, pledging to accelerate the country’s nuclear and missile capabilities. It was North Korea’s first missile launch since Nov. 5 and coincided with a visit by U.S. Secretary of State Antony Blinken to South Korea, where he pledged bilateral and trilateral cooperation including Japan to respond to Pyongyang’s growing military threats. The test occurred less than two weeks before U.S. President-elect Donald Trump, who held unprecedented summits with Kim during his